Kills local voxels if voxel server is removed from NodeList
- added notification hooks to NodeList
- implemented hooks in VoxelSystem to kill local voxels when
  voxel server is killed
Merge branch 'master' of https://github.com/worklist/hifi into multiple_voxel_servers
fix compiler warning
small tweak
adding jurisdiction to scene stats to implement add/drop effect, added command line to voxel server to not send environments
correctly handle freeing of memory for _jurisdictionRoot in VoxelSceneStats
Merge branch 'master' of https://github.com/worklist/hifi into multiple_voxel_servers

Conflicts:
	libraries/avatars/src/HandData.h
added notifications with jurisdiction details for when voxel servers come and go
added visulization for voxel add/kill
fix build buster
Merge branch 'master' of https://github.com/worklist/hifi into multiple_voxel_servers

Conflicts:
	interface/src/Application.cpp
Merge pull request #794 from ZappoMan/multiple_voxel_servers

Visualization for Voxel Server Add/Kill